1 Welcome – Thanks for joining this ITRC Training Class Biofuels Biofuels: Release Prevention, Environmental Behavior, and Remediation Sponsored by: Interstate Technology and Regulatory Council (www.itrcweb.org) Hosted by: US EPA Clean Up Information Network (www.cluin.org) 2 Housekeeping Course time is 2¼ hours Question & Answer breaks • Phone - unmute *6 to ask question out loud Simulcast - ? icon at top to type in a question Turn off any pop-up blockers • Download slides as PPT or PDF Go to slide 1 Move back 1 slide Move forward 1 slide Move through slides • Arrow icons at top of screen • List of slides on left Feedback form available from last slide – please complete before leaving This event is being recorded Go to last slide Go to seminar homepage Submit comment or question Report technical problems Copyright 2012 Interstate Technology & Regulatory Council, 50 F Street, NW, Suite 350, Washington, DC 20001 3 ITRC Disclaimer This material was sponsored by an agency of the United States Government. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof and no official endorsement should be inferred. The information in ITRC Products was formulated to be reliable and accurate. However, the information is provided "as is" and use of this information is at the users’ own risk. Information in ITRC Products is for general reference only; it should not be construed as definitive guidance for any specific site and is not a substitute for consultation with qualified professional advisors. ITRC Product content may be revised or withdrawn at any time without prior notice. ITRC, ERIS, and ECOS make no representations or warranties with respect to information in its Products. ITRC, ERIS, and ECOS will not accept liability for damages of any kind that result from acting upon or using this information. ITRC, ERIS, and ECOS do not endorse or recommend the use of specific technology or technology provider through ITRC Products. 4 ITRC (www.itrcweb.org) – Shaping the Future of Regulatory Acceptance Host organization Network • State regulators • • • • All 50 states, PR, DC • Federal partners DOE DOD EPA • ITRC Industry Affiliates Program Wide variety of topics Technologies Approaches Contaminants Sites Products • Technical and regulatory guidance documents • Internet-based and classroom training • Academia • Community stakeholders 5 ITRC Course Topics Planned for 2012 – More information at www.itrcweb.org Popular courses from 2011 New in 2012 Green & Sustainable Bioavailability Considerations for Contaminated Sediment Sites Remediation Biofuels: Release Prevention, Environmental Incremental Sampling Behavior, and Remediation Methodology Decision Framework for Applying Attenuation Integrated DNAPL Site Processes to Metals and Radionuclides Strategy Development of Performance Specifications for Solidification/Stabilization 2-Day Classroom Training: LNAPL 1: An Improved Understanding of Light Nonaqueous-Phase LNAPL Behavior in the Subsurface Liquids (LNAPLs): LNAPL 2: LNAPL Characterization and Science, Management, Recoverability - Improved Analysis and Technology LNAPL 3: Evaluating LNAPL Remedial Technologies for Achieving Project Goals October 16-17, 2012 in Novi, Mine Waste Treatment Technology Selection Michigan (Detroit Area) Phytotechnologies Permeable Reactive Barrier (PRB): Technology Update Project Risk Management for Site Remediation Use and Measurement of Mass Flux and Mass Discharge Use of Risk Assessment in Management of Contaminated Sites 6 Meet the ITRC Instructors Mike Maddigan Pennsylvania Department Environmental Protection Harrisburg, PA 717-772-3609 [email protected] Denice Nelson ARCADIS-US, Inc. Minneapolis, MN 612-386-4618 denice.nelson @arcadis-us.com David Tsao Mark Toso BP Naperville, IL 630-420-5147 [email protected] Minnesota Pollution Control Agency St. Paul, MN 651-757-2158 mark.toso @state.mn.us 7 Biofuels and the Environment What are biofuels and why are they important? Are there equipment compatibility issues associated with biofuels? How do biofuel releases impact the environment? Do biofuels behave differently in the environment than petroleum-based fuels? How should biofuels releases be cleaned up? 8 What You Will Learn Scope of potential environmental challenges Differences between biofuel and petroleum fuel behavior Biofuel supply chain, potential release scenarios, and release prevention How to develop an appropriate conceptual model for the investigation and remediation of biofuels Appropriate investigation and remediation strategies How to assess the behavior of new biofuels when alternatives come on the market 9 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 = hypothetical case study 10 Our Hypothetical Case Study Dispenser System Dispensing Station Vadose Zone Underground Storage Tank System (UST) Capillary Fringe Aquifer Groundwater Flow Direction 11 What Are Biofuels? For the purposes of this training, the term biofuel is applied to liquid fuels and blending components produced from renewable biomass feedstocks used as alternative or supplemental fuels for internal combustion engines. 12 Important Terms Denatured Fuel Ethanol (DFE) – fuel ethanol made unfit for beverage use by the addition of a denaturant; also called E95. FAME (Fatty Acid Mono-alkyl or Methyl Esters) – Transesterified oils derived from vegetable oils or animal fats, blended with or used in place of conventional diesel fuels. Biofuel Blend – Mixture of biofuel and conventional petroleum-based fuel. Conventional Fuel – A mixture of compounds, called hydrocarbons, refined from petroleum crude, plus additives to improve its stability, control deposit formation in engines, and modify other characteristics. 13 Why be Concerned with Biofuel Releases? Catastrophic impact of large releases • Large releases from tank car train derailments • Massive fires Smaller releases • Slow leaks can go 2009 train derailment in Rockford, IL resulting in 435,000-gallon DFE release. undetected (such as in storage tanks) • Large volume - severe environmental impacts Photos from NTSB Scorched rail cars after fire in the Rockford, IL release. 14 Petroleum vs. Biofuel Releases Behave differently in the environment • Site characterization and remediation strategy • Safety risks • Potential release points For more info on LNAPL training go to http://www.itrcweb.org 15 Federal Renewable Fuel Mandates Energy Policy Act of 2005 • First Renewable Fuel Standard (RFS) program • Required 7.5 billion gallons of renewable fuel to be blended into gasoline by 2012 Energy Independence & Security Act of 2007 • Renewable fuel requirements increased 9 billion gallons (2008) 36 billion gallons (2022) Additional alternative fuel objectives for federal Alternative Fuel Vehicle (AFV) fleets 16 State Renewable Fuel Mandates Table 1-3 WA MT OR MN PA MO NM LA FL HI MA 17 International Mandates European Union • Directive 2003/30/EC • Promotes biofuels use in transportation sector • Proposes non-mandatory biofuels use targets Brazil • Has required the use of biofuels since 1976 18 ITRC Guidance: Biofuels: Release Prevention, Environmental Behavior, and Remediation 1. Biofuel basics 2. Release prevention and response planning 3. Fate & transport (F&T) of biofuels in the environment 4. Characterizing release sites 5. Long-term response strategies 6. Stakeholder concerns 19 What is Not Covered Vegetable oils, recycled greases, and fuels indistinguishable from petroleum-based fuels Air quality Sustainability Detailed information on manufacturing processes End-user considerations Biofuel policies Fuel additives 20 Applying the ITRC Document Before a Release Release prevention • Ensure materials compatibility • Update best management practices Release response planning • Fire/explosion threats • Rapid containment 21 Applying the ITRC Document After a Release Site characterization, sampling, F&T modeling • Physical, chemical, and biological properties • Developing Site Conceptual Model (SCM) Long-term responses • Determining remediation strategy • Assessing hazards and risks Stakeholder concerns • Location of incident • Timing of response Emerging biofuels • Multi-media evaluation process 22 Ethanol Fuel Blends (Table 1-1) ASTM Standard No adopted standard Fuel Description E85 A commercial trade name representing an alternative fuel consisting of 70%–85% DFE by volume as defined in the EPAct of 1992 Ethanol fuel blends for flexible-fuel vehicles Intermediate ethanol blends E10 Fuel produced for use in ground vehicles equipped with flexible-fuel spark-ignition engines containing 51%–83% ethanol; may be referred to at retail as “ethanol flex-fuel” Intermediate blends of DFE and gasoline >E10 and <E51 D5798-11 Gasoline with up to 10% DFE by volume D4814 (standard for gasoline) “Neat Ethanol” (E100) is non denatured ethanol No adopted standard 23 Biodiesel and Biodiesel Blends (Table 1-2) Fuel Description ASTM Standard B100 Biodiesel fuel blend stock; legally registered as a fuel and fuel additive with USEPA under Section 211(b) of the Clean Air Act D6751-11 >B20 to <B100 A blend of petroleum-distillate and biodiesel fuel that contains between 21% to 99% biodiesel No standard adopted >B5 to B20 A blend of petroleum-distillate and biodiesel fuel that contains between 6% to 20% biodiesel D7467-10 Up to B5 Fuel blends of up to 5% biodiesel fuel are considered a fungible component of conventional petroleum-based diesel fuel D975 (same as petroleum standard) “Neat Biodiesel” is biodiesel not blended with petroleum-based diesel and is designated as “B100” 24 Biofuel Production Projections (Figures 1-1 and 1-2) World Ethanol Production Projections (millions of gallons) 35,000 25,000 15,000 World Biodiesel Production Projections (millions of gallons) 6,000 5,000 4,000 3,000 25 Opportunities to Use this Document in Your State Connection to your state vapor intrusion regulations or guidance • Fate & transport modeling • Indoor air modeling Equipment compatibility requirements • Storage tank programs • Bulk transport requirements Facility response plans • Emergency response • Spill Prevention Control and Countermeasures (SPCC) plans 26 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 27 Biofuel Releases (Section 2) This section will cover Release Scenarios and Frequencies Release Causes Prevention Emergency Response Planning Evaluated based on the differences between petroleum and biofuel supply chains 28 Petroleum vs. Biofuel Supply Chains (Combined Figures 2-1 and 2-2) Manufacturing Refinery –OR– Facility (Bulk) Transport Bulk Depot / Supply Terminal (Blended) Distribution Pipeline Components Truck AST AST Rail Piping & Manifold Piping & Manifold Dispensing Station UST System UST Product Piping Truck Loading Rack Barge Unloading / Loading Rack Dispenser 29 Release Scenarios and Incidents (Section 2.1) Transport Rail Truck Barge Volume and Incident Frequencies (Table 2-1): Potential Volume Incident Frequency Tanker trucks: ~8,000 to 10,000 gallons per truck 1,000 road accidents per year (1 in 25,000 deliveries) Railcars: ~25,000 to 30,000 gallons per railcar; unit trains 70-100 cars 2,000 derailments per year (severity not specified) Tank barges: ~420,000 to 630,000 gallons per barge typical 2.16 gallons spilled per 1 million gallons moved Pipeline If all bulk gasoline and diesel currently transported was used to produce E10 and B5, then bulk biofuels transport needs would be: • 1,250 tanker trucks, • 415 railcars, or PER DAY • 20 tank barges Distribution Truck 30 Release Causes (Section 2.2) Leak Detection Issues, Release Causes (Table 2-2): Equipment Detection Causes Underground Storage Tank (UST) System Small volume or chronic releases may not be detected if commercial leak detection equipment is incompatible Incompatible materials; solvent nature of biofuels scouring sediment, sludge, rust, and scale built up in tank previously storing conventional fuels Acute, large volume releases detected through automated volume reconciliation accounting Dispenser System Small volume or chronic releases detected through standard inspections Incompatible materials; filters plugging due to insufficient rate of changeouts Dispensing Station UST System UST Product Piping Dispenser 31 Selected Biofuel Release Information (Table D-2, Appendix D) Site Fuel Volume in gallons (Section 2.1) Causes (Section 2.2) PNW Terminal, OR DFE 19,000 AST release Maxville, Ontario Balaton, MN South Hutchinson, KS Cambria, MN Storrie, CA Rockford, IL Williams County, OH DFE 26,000 60,000 28,000 25,000 30,000 55,000 – 75,000 80,000 Derailment Wood River, NE DFE 20,000 Loading railcar Rice, MN Hastings, MN E85 700 800 UST release St. Paul, MN Biodiesel 29,000 AST release See Appendix D: fate and transport evaluation (Section 3), analytes investigated (Section 4), and response activities conducted (Section 5) 32 Release Prevention (Section 2.3) Compatible materials and equipment • Plastics, polymers, and elastomers • Metal components and solders • Commercial leak detection equipment Management practices • Changing out filters more frequently can ITRC, Biofuels-1, Figure 2-7 prevent clogging issues • Proper Operations & Maintenance and frequency on leak detection equipment prevents undetected releases Appendix B (checklist) provides guidance on compatibility of UST systems for biofuels ITRC, Biofuels-1, Figure 2-5 33 Emergency Response Planning (Section 2.4) Applicable plans • Spill Prevention Control and Countermeasures (SPCC) regulations (40 CFR 112) • Facility Response Plans (FRP) Additional Emergency Response considerations • • • • Common fire-fighting foams – less effective Appropriate foams – less available Sorbent booms – miscibility, sorption, etc. Impacts to sensitive receptors – oxygen demand, biodegradability, etc. 34 Our Case Study: The Release Release Volume (Section 2.1) 10,000 gallons E85 released from a UST that was switched from storing E10 Release Cause (Section 2.2) E85 scoured the sludge, rust, sediment, & scale Release Prevention (Section 2.3) Guidance on converting tanks to E85 NOT used 35 Biofuel Releases Summary (Section 2) Biofuel releases will occur somewhere along the supply chain Current case studies (Appendix D) indicate they occur more often in association with bulk transport or during storage Frequency is likely to increase as storage and handling increases Root causes are often materials compatibility and management practices associated with equipment Can be addressed to prevent releases such as using the tank conversion checklist (Appendix B) Resources for emergency response preparedness are also available 36 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 37 Fate and Transport (Section 3) This section will cover: Biofuel Properties Surface and subsurface behavior Effects on microbial communities and byproduct formation Impacts on petroleum hydrocarbons and NAPL Use of the hypothetical case study to help illustrate key points 38 Properties of Selected Fuel Components (Table 3-1) Solubility (mg/L) Henry’s Vapor Law Pressure Constant (mm Hg) (unitless) Biodegradation Potential Implications Ethanol Infinite 2.1E-4 to 59 2.6E-4 Aerobic: hours to days Anaerobic: days to weeks Readily partitions to water and dilutes according to availability. Rapidly biodegradable Benzene 1,800 0.22 Aerobic: days to months Anaerobic: years Readily partitions to vapor phase from NAPL and from water 75 Summary of some of the more pertinent properties of biofuels and reference compounds (benzene and diesel) • Provides a generalized summary of implications relating to these properties • Expanded property table available in Appendix C of the document Table excerpts provided for the E85 case study 39 Behavior in Surface Spills (Section 3.5.1 and 3.5.2) Initial fate can be controlled by • • • • Vaporization Ignition and consumption by fire Surface drainage Surface water dilution Immediate short-term impacts on surface water biota • Aquatic species toxicity (Section 1.6) Ethanol and isobutanol: aquatic toxicity values range from 1,000 mg/L to > 14,000 mg/L Biodiesel: numerical values currently not available (area of research) • Dissolved oxygen depletion Can result in detrimental impacts to aquatic life (i.e. fish kills) 40 Behavior in the Subsurface: Petroleum Hydrocarbons (Figure 3-1) ITRC LNAPL guidance and training available for additional information on LNAPL distribution – www.itrcweb.org/LNAPLs Trapped and sorbed residual Volatilization NAPL body Dissolved phase plume Aquifer Groundwater flow direction Groundwater source (longer term) Capillary fringe Unsaturated zone Primary source (short term) 41 Behavior in the Subsurface: Ethanol Blends (Figure 3-5) Conventional gasoline (E0) E10 DFE High permeability water-filled lens Pore water containing ethanol Immobile gasoline phase capillary fringe aquifer (collapsed) capillary fringe Dissolution to groundwater Ethanol blends behave differently than low solubility biofuels or petroleum compounds • Ethanol fraction will partition into soil moisture present within the vadose zone and capillary fringe • Once in contact with groundwater, will migrate • Likelihood of ethanol reaching groundwater is dependent on release scenario (large spills more likely to reach water table) 42 Potential Media Impacts by Equipment Type (Table 3-2) Table objective: provide information regarding potential release points, release volumes and media that can be affected by release Example for E85 case study (UST release) Equipment Type Potential Media Impacts Underground storage • Surrounding backfill and soil in the UST “pit” tank systems • Groundwater impacts depend on the proximity of the (Section 2.2.5) water table to the UST as well as a sufficient driving force to cause the biofuel to percolate to depth • Dispensing stations • If groundwater is impacted, cosolvency issues may be • May be present at present if historic petroleum releases have occurred at manufacturing the same location facilities and bulk depots/supply terminals 43 Biochemical Oxygen Demand (Section 18.104.22.168) Release of biofuel into an aqueous environment will result in rapid consumption of dissolved oxygen (DO) In groundwater, rapid biodegradation will induce anaerobic conditions Dead paddlefish resulting from a release of Wild Turkey Bourbon 44 Biofuel Biodegradation (Figure 3-2) Biofuels more readily biodegradable Methane CO2 H2 Ethanol CO2 Acetyl CoA Butyryl CoA AcetoacetylCoA Butanol Butyrate CO2 Acetone Acetate Methane Figure 3-2. Major routes of the anaerobic fermentation of ethanol 45 Factors Affecting Biodegradation Inhibition of biological degradation at high concentrations (6% - 10% ethanol) Rate affected by • Available electron acceptors • Nutrients • pH (optimal = 6-8) Production of volatile fatty acids during metabolism can lower pH 46 Methane Hazards (Figure 3-4) Methane is a flammable gas • Lower explosive limit (LEL) = 5% in atmosphere • Upper explosive limit (UEL) = 15% in atmosphere LEL equivalent concentration in groundwater • 1 - 2 mg/L • Dependent on temperature Figure source: 30 CFR 57.22003 20% 16% Oxygen Mixtures which cannot be produced from methane and air Explosive Capable of forming explosive mixtures with air 12% 8% Not capable of 4% forming explosive mixtures with air 0 0 4% 8% 12% 16% 20% Methane Relationship Between Quantitative Composition and Explosivity of Mixtures of Methane and Air 47 Generation of Methane Methanogens utilize acetate and hydrogen • Partitioning between dissolved and gaseous methane concentrations • Dissolved methane concentration dependent on groundwater temps Delays (months to years) in methane production have been observed in both lab and field studies Methane soil gas may undergo attenuation in the vadose zone Estimated Soil Gas Methane (%) (Figure 3-3) 100 80 60 40 Temperature (70oF) Temperature (45oF) 20 0 0 10 20 30 40 Dissolved Methane (mg/L) 48 Preferential Biodegradation of Biofuels Over COCs (Section 3.4.3 and 3.4.4) Readily degradable nature of biofuels can result in preferential biodegradation of biofuels over COCs Plume elongation expected to be temporary Elongated plumes may have shorter lifetimes because of lower concentrations of petroleum hydrocarbons and buildup up biomass Redox changes in the subsurface may lead to changes in the mobilization of metals 49 Enhanced Solubility of Petroleum (Section 3.4.1) Some biofuels can act as cosolvent • High concentrations (> 20% ethanol) • May occur within capillary fringe • Unlikely to occur in groundwater Releases of highly soluble biofuels (e.g. ethanol) onto prior hydrocarbon releases • May result in mobilization of pre-existing residual separate phase hydrocarbons • Section 3.4.2 50 Our Case Study: Fate & Transport Media impacts to vadose zone, capillary fringe and groundwater • Capillary fringe can act as a lingering source area for ethanol Groundwater will become anaerobic, possibly leading to methane generation CH4 51 Fate and Transport Summary Property differences between biofuels and petroleum fuels influence fate and transport in the environment Highly soluble biofuels readily partition into water Biodegradable nature of biofuels significantly impacts dissolved oxygen concentrations Ethanol can be retained in the capillary fringe (lingering source) Cosolvency effects likely limited to capillary fringe and large E95 releases Potential for significant methane generation Temporary plume elongation 52 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 53 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 54 Site Investigation (Section 4) This section will cover: Risk Drivers Monitoring CH4 Analytical Methods Site Closure Considerations Use of the hypothetical case study to help illustrate key points 55 Risk Drivers for Site Investigation Surface water • Ethanol can not be recovered due to solubility; biodiesel can be recovered like petroleum • Dissolved oxygen depletion – risk to aquatic species a significant new concern Vadose zone • Explosive risk from increased methane production – NO ODOR • Potential increased vapor intrusion (VI) risk for petroleum VOCs Groundwater • Risk to drinking water supplies due to plume elongation • Biofuel degradation can produce taste and odor issues in drinking water supplies 56 Our Case Study: Site Investigation (Section 4) Site investigation strategy: • Dependent on age, volume, composition of release • Potential risk receptors Case study: • Recent E85 spill • Dispensing station building and surrounding residential area CH4 57 Site Investigation – What’s Different Different chemical and physical properties of biofuels require changes to investigation design • Monitoring well screen length and type • Additional analytical parameters Additional vapor risk assessment for VOCs and methane (if receptors are present) Time factor • Longer monitoring duration needed to assess risk 58 Methane Monitoring (Section 4.1.1) Biofuels have the potential to generate significantly more methane than petroleum Initial evaluation should determine if explosive conditions exist Methane appearance may not be immediate, suggesting extended monitoring when receptors are present • Low or no initial methane may not mean no future risk • May appear without detection of source biofuel Subsurface methane may be sampled in: • Soil gas using push probes or vapor points • Groundwater using push probes or wells for dissolved methane 59 Methane Monitoring (Section 4.1.1) Groundwater • Generally more reliable than soil gas for detection • Well screen lengths may affect concentrations • Must closely follow QA/QC sampling procedures • Methane is easily lost during sampling • Levels above 25 mg/L indicate saturated levels where ebullition (bubbling) may be occurring Soil gas • Sampling points and procedures same as VOCs (ITRC 2007, Vapor Intrusion Pathway: A Practical Guideline) • If potential receptors are present at least one vapor monitoring point should be placed in the release area 60 Delayed Methane Generation: Cambria, MN Case Study July 2007 (Appendix D) 61 Delayed Methane Generation: Cambria, MN Case Study December 2007 (Appendix D) 62 Ethanol Monitoring (Section 4.1.2) Vadose zone • Soil gas monitoring same as VOCs • Soils can be sampled using standard VOC methodology Capillary fringe • Lysimeters have been used, but sampling capillary fringe not necessary Groundwater • Shorter monitoring well screens recommended to capture ethanol draining, and/or leaching from the capillary fringe • Multi-level wells may be needed • Detection of ethanol in groundwater should not be used alone for methane risk assessment 63 Cambria, MN Case Study Soil Sample 6,340,000 ug/kg Ethanol Aq. Ethanol Capillary fringe MW-20 (5’ screen) 6,100,000 ug/L Groundwater MW-1 (10’ screen) ND Note: Not in ITRC document 64 Biodiesel Monitoring (Section 4.1.3) Biodiesel forms a LNAPL on groundwater • Wire wrapped screens are recommended to help facilitate the entry of higher viscosity biodiesel LNAPL into monitoring wells • TarGOST (LIF) has been shown to effectively map B100 NAPL No standard analytical methods for biodiesel in soil or groundwater exist but surrogates can be used • Bugs immediately hydrolyze FAMEs to fatty acids • TOC/DOC and COD to quantify dissolved fraction in groundwater • TOC can also be used to quantify biodiesel in soil • Degradation products (e.g. short chain fatty acids) • Surrogates do not directly quantify the concentration of biodiesel, but are useful to evaluate groundwater impact and methane generation potential 65 Biodiesel Monitoring (Section 4.1.3) Biodiesel (B100) produces a lot of methane (and CO2) Like ethanol ebullition (bubbling) may increase methane risks, and VI risks for blended fuels 1.4L FAME → 662 L methane Biodiesel also has a taste/odor/appearance impact on water quality Petroleum fraction of blends may be the risk driver for biodiesel blends; however methane may still be an issue for higher percentage blends 66 Surface Water Monitoring (Section 4.1.4) Depletion of dissolved oxygen and the affect on aquatic life is primary concern with soluble biofuels (e.g. ethanol) DO may be measured directly in the field COD, DOC and/or TOC may be used to assess the potential oxygen consumption load 67 Field Screening Methods (Table 4-1) Table for Sampling and Analytical Methods (Table 4-1) Analyte Environmental Media Analytical Methods Field Methods Methane Soil Gas Infrared landfill gas meter Methane (LEL) Soil Gas Explosimeter Ethanol/butanol Soil Gas Photoionization detector DO Surface Water Field meter, kit, or titration BOD Surface Water Field meter or kit 68 Analytical Laboratory Methods (Table 4-1) Analyte Environmental Media Analytical Methods Methane Soil Gas USEPA 3C; ASTM D1946 Dissolved Methane Groundwater RSK-175 Acetate Groundwater Ion chromatography, other DOC/TOC Surface Water, Soil, Groundwater Standard Method 5310C; ASTM D513-6; USEPA 415.3 BOD/COD Surface Water USEPA Methods 405.1 (BOD); 410.1 #DR/3000 (COD), or similar Ethanol/butanol Soil USEPA 8260B Ethanol/butanol Soil Gas USEPA Method TO-15 Ethanol/butanol Groundwater USEPA 8260B; USEPA 8260; USEPA 8015C; USEPA 8261A 69 Our Case Study: Site Investigation Monitor soil gas near receptor (CH4, VOC) Install vapor point near receptor Shorter-screened wells in source area Monitoring for additional parameters CH4 Use shorter screened wells in source area Monitor the groundwater (diss. CH4, EtOH, VOC, Acetate 70 Site Investigation Summary (Section 4) Methane in soil gas = likely risk driver Physical properties of biofuels may require some changes to a site investigation design, such as monitoring wells Sampling for additional parameters will likely be required Additional field screening equipment may be required Additional VI monitoring may be required due to • Stripping of petroleum VOCs from groundwater and advection of petroleum vapor by methane and other biogenic gases • Methane exerts a large oxygen demand which can allow petroleum vapors and methane to migrate further Site investigation of other or new biofuels should be based on the physical, chemical, and biological properties of the biofuel 71 Site Closure Considerations Was the site investigation adequate for a biofuel release? Have all groundwater and vapor risks been identified? Are degradation products still present in groundwater (e.g. methane, acetate) Has monitoring adequately accounted for delayed methane generation? If elevated risks and hazardous conditions exist, remediation may be required 72 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 73 Long-Term Response Strategies (Section 5) This section will cover: General considerations for remediation Risk management Remedial selection CH4 Use of the hypothetical case study to help illustrate key points 74 Our Case Study: Long-Term Response Strategies (Section 5) Requires consideration of: Case study: • Type of biofuel • Extent and magnitude of the • E85 spill • Media impacted: • Vadose zone • Capillary Fringe • Groundwater • State regulations applicable to release • Regulatory threshold for a COC(s) • Risk to identified receptors gasoline components • Dispensing station building and surrounding residential area CH4 75 Generalized Framework (Figure 5-1) Site Conceptual Sections 3 and 4 Model/Site Characterization Sect 5.1 Above regulatory threshold and/or a potential hazard exists? Yes Risk Sect 5.2.1 acceptable or No manageable w/ controls? Sect 5.2.2 Implement closure Sect 5.3.3 monitoring and/or controls Meet Sect 5.4 No Further Action/Site Closure Yes Active Remedy Yes Yes No Sect 5.3 Meet closure requirements? No remedial endpoints? Yes No 76 Risk Management (Section 5.2.1; Table 5-1) Management of risk through long-term monitoring Controls (institutional or engineering) • Provide protection from exposure to contaminant(s) Implement closure monitoring and/or controls that exist or remain on a site Benefits Limitations Dissolved biofuel is readily biodegradable without additional enhancement • High concentrations of some dissolved biofuel constituents (i.e., ethanol) can be toxic to microorganisms • Delayed biodegradation of more recalcitrant contaminants via preferential biodegradation of the biofuel • Does not address immediate risks • High potential for methane generation • Does not address LNAPL, although microbial processes can enhance dissolution in groundwater • Surface water may become anoxic, impacting aquatic species and habitat 77 Selection of Remedial Technology (Tables 5-2 and 5-3) Active remedy • Eliminate or reduce the remediation driver or COC Remedial technologies Active • Soils/Sediment (Table 5-2) Remedy • Groundwater/Surface water (Table 5-3) Categorized as in situ or ex situ Subdivided within each category by dominant remedial mechanism • Biological technologies (e.g. enhanced aerobic biodegradation) • Chemical (e.g. chemical oxidation) • Physical (e.g. soil vapor extraction) Provides discussion on overall benefits and limitations of each technology to help guide selection 78 Remedial Technology (Soils Example) Table 5-2 Examples applicable to E85 impacts to vadose zone/capillary fringe Technology Active Remedy Benefits Limitations Rapidly removes readily strippable compounds (constituents with a high Henry's Law Constant, vapor pressure, and/or biodegradability). Promotes aerobic biodegradation of biofuels and methane oxidation (if present). Not effective for constituents with a low Henry's Law Constant, vapor pressure, and/or biodegradability; may require ex situ vapor treatment. Can result in rapid elimination of dissolved constituents and increase in dissolution and subsequent biodegradation of residual NAPL. Promotes methane oxidation. Likely inhibits formation of anaerobic conditions and methane generation. Does not directly address LNAPL. High concentrations of some dissolved biofuel constituents (e.g. ethanol) can be toxic to microorganisms. Physical In Situ Treatment Soil vapor extraction (SVE) Soil Biological Enhanced Aerobic Biodegradation Bioventing - soil 79 Detailed Remedial Technology Tables (Tables 5-4a through 5-4c) Biofuels evaluated Active Remedy • Ethanol (Table 5-4a) • Butanol (Table 5-4b) • Biodiesel (Table 5-4c) Identifies targeted environmental media Evaluates technology by specific property (e.g. solubility) and provides numerical values Compares efficiency to a reference petroleum hydrocarbon compound Summarizes which compound (biofuel or reference hydrocarbon) is favored by the remedial technology 80 Example Table 5-4a (Figure 5-2) Expanding on the examples selected from Table 5-2 as applicable to vadose zone remediation of the E85 case study: Technology Target Media VZ GW SVE X Bioventing X Depicts the media that the technology is applicable to Active Remedy P/C/B Properties Benzene Ethanol Favors Vapor Pressure 75 mm Hg 49 -56.6 mm Hg Benzene Aerobic Bio Potential days hours Ethanol Aerobic Bio Potential days hours Ethanol SW Describes what physical, chemical or biological properties are affected by the technology Property values for benzene (reference compound for ethanol) Property values for ethanol Describes which compound the technology favors with respect to the targeted property 81 Example Table 5-4d (Methane) Evaluates technology effectiveness on methane remediation versus methane generation Technology Target Media VZ GW SVE X Bioventing Depicts the media that the technology is applicable to X Active Remedy P/C/B Properties Methane Remediation Methane Generation Vapor Pressure Applicable N/A Aerobic Bio Potential Applicable Inhibits Aerobic Bio Potential Applicable Inhibits SW Describes what physical, chemical or biological properties are affected by the technology Evaluates whether technology can remediate methane, and by which P/C/B property Specifies whether technology inhibits methane generation, and by which P/C/B property 82 Our Case Study: Long-Term Response Strategies Application of SVE for vadose zone: • Physical removal • Enhanced biodegradation Long-term monitoring for both soil gas and dissolved plume to assess and re-evaluate risk Additional technologies can be evaluated/implemented CH4 83 Long-Term Response Strategies Summary Response strategies should be based on risks presented by biofuel release MNA may be a viable response strategy If methane is a concern, longer-term monitoring and/or engineering controls may be warranted Technology evaluation process can be applied to biofuels, the petroleum component of the blend, and future biofuels 84 Training Roadmap Introduction Releases Fate and Transport Q&A Session #1 Site Investigation Long-Term Response Strategies Summary Q&A Session #2 85 Our Case Study: Summary Equipment compatibility issues Biofuels fate & transport in the environment Methane gas generation Site investigation design Monitoring in environmental media Long-term response strategies Risk management CH4 86 Overall Summary Biofuel production and consumption is increasing = increase in potential frequency of releases = potential for environmental impacts By using the ITRC document, you will be prepared and able to: • • • • Build a better Site Conceptual Model (SCM) Understand fate & transport in the environment Know how to investigate a biofuel release site Formulate a better response strategy 87 Thank You for Participating 2nd question and answer break Links to additional resources • http://www.cluin.org/conf/itrc/biofuels/resource.cfm Feedback form – please complete • http://www.cluin.org/conf/itrc/biofuels/feedback.cfm Need confirmation of your participation today? Fill out the feedback form and check box for confirmation email.